/**
 * @file
 * MQTT client
 */

/*
 * Copyright (c) 2016 Erik Andersson
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
 * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * This file is part of the lwIP TCP/IP stack.
 *
 * Author: Erik Andersson
 *
 */
#ifndef LWIP_HDR_APPS_MQTT_CLIENT_H
#define LWIP_HDR_APPS_MQTT_CLIENT_H

#include "lwip/apps/mqtt_opts.h"
#include "lwip/err.h"
#include "lwip/ip_addr.h"
#include "lwip/prot/iana.h"

#ifdef __cplusplus
extern "C" {
#endif

typedef struct mqtt_client_s mqtt_client_t;

#if LWIP_ALTCP && LWIP_ALTCP_TLS
struct altcp_tls_config;
#endif

/** @ingroup mqtt
 * Default MQTT port (non-TLS) */
#define MQTT_PORT LWIP_IANA_PORT_MQTT
/** @ingroup mqtt
 * Default MQTT TLS port */
#define MQTT_TLS_PORT LWIP_IANA_PORT_SECURE_MQTT

/*----------------------------------------------------------------------------------------------
 */
/* Connection with server */

/**
 * @ingroup mqtt
 * Client information and connection parameters */
struct mqtt_connect_client_info_t {
    /** Client identifier, must be set by caller */
    const char *client_id;
    /** User name, set to NULL if not used */
    const char *client_user;
    /** Password, set to NULL if not used */
    const char *client_pass;
    /** keep alive time in seconds, 0 to disable keep alive functionality*/
    u16_t keep_alive;
    /** will topic, set to NULL if will is not to be used,
        will_msg, will_qos and will retain are then ignored */
    const char *will_topic;
    /** will_msg, see will_topic */
    const char *will_msg;
    /** will_msg length, 0 to compute length from will_msg string */
    u8_t will_msg_len;
    /** will_qos, see will_topic */
    u8_t will_qos;
    /** will_retain, see will_topic */
    u8_t will_retain;
#if LWIP_ALTCP && LWIP_ALTCP_TLS
    /** TLS configuration for secure connections */
    struct altcp_tls_config *tls_config;
#endif
};

/**
 * @ingroup mqtt
 * Connection status codes */
typedef enum {
    /** Accepted */
    MQTT_CONNECT_ACCEPTED = 0,
    /** Refused protocol version */
    MQTT_CONNECT_REFUSED_PROTOCOL_VERSION = 1,
    /** Refused identifier */
    MQTT_CONNECT_REFUSED_IDENTIFIER = 2,
    /** Refused server */
    MQTT_CONNECT_REFUSED_SERVER = 3,
    /** Refused user credentials */
    MQTT_CONNECT_REFUSED_USERNAME_PASS = 4,
    /** Refused not authorized */
    MQTT_CONNECT_REFUSED_NOT_AUTHORIZED_ = 5,
    /** Disconnected */
    MQTT_CONNECT_DISCONNECTED = 256,
    /** Timeout */
    MQTT_CONNECT_TIMEOUT = 257
} mqtt_connection_status_t;

/**
 * @ingroup mqtt
 * Function prototype for mqtt connection status callback. Called when
 * client has connected to the server after initiating a mqtt connection attempt
 * by calling mqtt_client_connect() or when connection is closed by server or an
 * error
 *
 * @param client MQTT client itself
 * @param arg Additional argument to pass to the callback function
 * @param status Connect result code or disconnection notification @see
 * mqtt_connection_status_t
 *
 */
typedef void (*mqtt_connection_cb_t)(mqtt_client_t *client, void *arg,
                                     mqtt_connection_status_t status);

/**
 * @ingroup mqtt
 * Data callback flags */
enum {
    /** Flag set when last fragment of data arrives in data callback */
    MQTT_DATA_FLAG_LAST = 1
};

/**
 * @ingroup mqtt
 * Function prototype for MQTT incoming publish data callback function. Called
 when data
 * arrives to a subscribed topic @see mqtt_subscribe
 *
 * @param arg Additional argument to pass to the callback function
 * @param data User data, pointed object, data may not be referenced after
 callback return, NULL is passed when all publish data are delivered
 * @param len Length of publish data fragment
 * @param flags MQTT_DATA_FLAG_LAST set when this call contains the last part of
 data from publish message
 *
 */
typedef void (*mqtt_incoming_data_cb_t)(void *arg, const u8_t *data, u16_t len,
                                        u8_t flags);

/**
 * @ingroup mqtt
 * Function prototype for MQTT incoming publish function. Called when an
 * incoming publish arrives to a subscribed topic @see mqtt_subscribe
 *
 * @param arg Additional argument to pass to the callback function
 * @param topic Zero terminated Topic text string, topic may not be referenced
 * after callback return
 * @param tot_len Total length of publish data, if set to 0 (no publish payload)
 * data callback will not be invoked
 */
typedef void (*mqtt_incoming_publish_cb_t)(void *arg, const char *topic,
                                           u32_t tot_len);

/**
 * @ingroup mqtt
 * Function prototype for mqtt request callback. Called when a subscribe,
 * unsubscribe or publish request has completed
 * @param arg Pointer to user data supplied when invoking request
 * @param err ERR_OK on success
 *            ERR_TIMEOUT if no response was received within timeout,
 *            ERR_ABRT if (un)subscribe was denied
 */
typedef void (*mqtt_request_cb_t)(void *arg, err_t err);

err_t mqtt_client_connect(mqtt_client_t *client, const ip_addr_t *ipaddr,
                          u16_t port, mqtt_connection_cb_t cb, void *arg,
                          const struct mqtt_connect_client_info_t *client_info);

void mqtt_disconnect(mqtt_client_t *client);

mqtt_client_t *mqtt_client_new(void);
void mqtt_client_free(mqtt_client_t *client);

u8_t mqtt_client_is_connected(mqtt_client_t *client);

void mqtt_set_inpub_callback(mqtt_client_t *client,
                             mqtt_incoming_publish_cb_t pub_cb,
                             mqtt_incoming_data_cb_t data_cb, void *arg);

err_t mqtt_sub_unsub(mqtt_client_t *client, const char *topic, u8_t qos,
                     mqtt_request_cb_t cb, void *arg, u8_t sub);

/** @ingroup mqtt
 *Subscribe to topic */
#define mqtt_subscribe(client, topic, qos, cb, arg)                            \
    mqtt_sub_unsub(client, topic, qos, cb, arg, 1)
/** @ingroup mqtt
 *  Unsubscribe to topic */
#define mqtt_unsubscribe(client, topic, cb, arg)                               \
    mqtt_sub_unsub(client, topic, 0, cb, arg, 0)

err_t mqtt_publish(mqtt_client_t *client, const char *topic,
                   const void *payload, u16_t payload_length, u8_t qos,
                   u8_t retain, mqtt_request_cb_t cb, void *arg);

#ifdef __cplusplus
}
#endif

#endif /* LWIP_HDR_APPS_MQTT_CLIENT_H */
